The present invention relates to a hydrocarbon conversion process. Particularly, the present invention relates to a method of improving the quality of an alkylate product from the catalyzed alkylation of olefin hydrocarbons.
The recent trend toward the production of oxygenates for gasoline blending can result in the removal of significant quantities of the butene isomer isobutylene from feedstocks to existing commercial alkylation processes. This is because isobutylene is a feedstock to certain etherification processes that produce the oxygenate compound of methyl tertiary butyl ether (MTBE). While MTBE is a gasoline blending component that has a relatively high octane blending value, there can be a partially offsetting octane debit to a gasoline pool that results from the removal of isobutylene alkylate produced from the hydrogen fluoride catalyzed alkylation of isobutylene, since isobutylene alkylate itself has a reasonably high octane blending value that is in the range of from about 92.5 to about 93.5. When the isomer of isobutylene is removed from a hydrogen fluoride alkylation process feed, the quality of the resultant alkylate will generally be diminished due to the presence of alkylate produced from the alkylation of 1-butene which has a lower octane blending value than that of isobutylene alkylate. The octane blending value of 1-butene alkylate can range from about 89 to about 90.